1. Field
The field of the invention is devices for constructing farm fences, particularly those comprising woven wire and chain link and/or barbed wire attached to spaced apart posts. With more particularity, the field is devices for unwinding such fencing wire from rolls or spools and tensioning it properly for attachment to the posts.
2. State of the Art
Most commonly, fencing, whether of barbed, woven wire or chain link, is unwound by rolling the spool or roll along a line of preset support posts leaving the fencing unrolled along the ground, attaching its end to a suitable post and then tensioning (stretching) it for attachment to the other posts. It is stretched by clamping the free end of the fencing and pulling upon it using a vehicle, a winch, a block and tackle, or manual levers or the like. Only limited lengths of fencing may be stretched by these procedures. Each length must be permanently attached to the posts before the next length of fence is constructed, and firm anchoring posts are required at both ends of each length. Numerous devices have been conceived to facilitate the initial unwinding of the fencing material along the post line. U.S. Pat. No. 444,219 discloses a cart rotatably carrying a spool of fencing material and moved along the post line to unwind the strand of wire. A ratcheted windless is then used in a separate operation to stretch the wire before attachment to the posts. U.S. Pat. No. 643,919 discloses a similar device, being adapted however to simultaneously unwind several barbed wire strands. For stretching after the unwinding, wire clamps secure each separate strand to a separate ratcheted winch for each strand of wire. U.S. Pat. No. 567,213 discloses another but similar device, this one being sled mounted. A braking member 22 is used to prevent "runaway" of the wire spool during rapid unwinding of the wire. It is retracted before the subsequent tensioning operation. The stretching appears to be done by using the wire spool itself as the spool of a windless. U.S. Pat. No. 802,579 discloses another arrangement for first unwinding a length of fencing wire and then tightening the separate strands by separate windlesses. Not shown in the prior art is any device which unwinds and stretches the fencing material in a single continuous operation, so that it may be successively attached to successive posts as it is unwound along the fence post line. The prior art, therefore, requiring separate unwinding and stretching operations, is not highly expedient, especially for constructing long fences.